Lorraine Faunas of New York and Quebec 313 
17 mm. long, the general convexity is about 3 mm., but the an- 
terior part of the carina rises nearly 4 mm. above the neighboring 
parts of the shell. The shell is concentrically wrinkled and 
striated, but these markings are not very conspicuous. The 
lateral lines of attachment of the septum are distinctly indicated 
and are illustrated by the accompanying figure. 
Locality. In the basal red clay shales of the Lowville, along the 
western shore of La Cloche peninsula, several feet above railroad 
level. Collected in 1912 by Aug. F. Foerste, and preserved in the 
Victoria Memorial Museum, at Ottawa, Canada, by the Geological 
Survey of Canada. No. 8406. 
46. Pterotheca pentagona, sp. nov. 
{Plate II. Figs. 1, 2) 
Shell symmetrical, moderately convex, at least in the present 
state of preservation, excepting close to the apex where the curva- 
ture of the shell toward the posterior margin is more pronounced. 
Posterior margin nearly straight or only moderately curved for 
a distance of 10 or 12 mm. on each side of the apex, and then curv- 
ing forward toward the lateral margins of the shell. Lateral 
margins nearly parallel, converging from a width of 48 mm. at 
the rear to 40 mm. toward the front, where the lateral margin 
forms another angle, curving inward toward the median part of 
the shell. A fifth angle is formed anteriorly, where the margin 
curves forward on approaching the median wing or carina. The 
length of the shell from the apex to the anterior part of the carina 
is at least 35 mm. and possibly 37 mm. The antero-lateral 
angles are estimated as about 28 mm. anterior to a line drawn 
transversely through the apex. 
Only the basal part of the carina along the anterior half of the 
shell is preserved. This suggests the presence of a carina at least 
10 mm. in height, and possibly higher. The shell is finely striated 
concentrically, the striae following the lateral and anterior out- 
lines of the shell; at the base of the carina they curve backward 
and upward suggesting a vertical slit anteriorly. In addition to 
the striae, the shell also is concentrically wrinkled, the wrinkles 
being best developed between the apex and the lateral margins. 
The lower side or aperture is partly traversed by a broad triangu- 
lar septum, with its apex at the apex of the shell, and with its 
